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Strange pulses lead astronomers to first ‘teardrop’ star ever found

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Citizen scientists have helped astronomers make a remarkable discovery. It isn’t a strange or even life-sustaining planet. Instead, it is a type of teardrop-shaped star that astronomers have been trying to find for decades.

NASA’s planet-hunting TESS telescope has been in space for over a year and a half now, looking for alien worlds around the nearest stars to Earth. It spots other exciting things, too, as it systematically scans the galaxy around us, such as asteroids, comets and distant supernovae.

When TESS gathered data on a star known as ‘HD 74423‘, it found something unexpected.

This artist’s impression depicts HD 74423, an eclipsing binary star system with an unusual twist. Credit: Gabriel Pérez (SMM-IAC)

First off, the star isn’t just one star, but two. Second, the two stars are close enough together that the smaller star is pulling on the larger one, shaping it into a teardrop.

Thirdly, and most strangely, the larger star was pulsing with a bizarre pattern.

Now, pulsating stars are not rare. Our own Sun does so on an 11-year cycle. When astronomers have located one up until now, though, they’ve found that the entire star pulsates. In the case of HD 74423, though, it only pulses on one side!

“As the binary stars orbit each other,” Paulina Sowicka, PhD student at the Nicolaus Copernicus Astronomical Center (CAMK PAN) and co-author of the study, said in a statement. “We see different parts of the pulsating star. Sometimes we see the side that points towards the companion star, and sometimes we see the outer face.”

It was citizen scientists, looking at the data on Zooniverse’s Planet Hunters TESS website, who spotted the curious way that this star behaved.

Robert Gagliano, with Yale University’s Planet Hunters, and Tom Jacobs, an amateur astronomer from Bellevue, WA, both noted a strange pattern embedded in HD 74423’s light curve.

HD-74423-teardrop-star-pulsesTESS Planet Hunters data for star HD 74423. Credit: Zooniverse.

As shown in the above graphic, HD 74423 brightens and dims with a regular pattern, which identifies it as an ‘eclipsing binary’. These two stars orbit around each other, and on each orbit, they pass in front of each other. The pair is brightest when we view them side by side. They dim slightly when the smaller companion passes in front of the larger star, and they are dimmest when the smaller star passes behind the larger star.

At the same time, though, Gagliano and Jacobs noticed the unusual ‘hiccups’ in the data (some examples are circled in yellow to highlight them). It was these ‘hiccups’ that pointed the researchers towards the idea that this was a new discovery and one that had been long sought-after.

“We’ve known, theoretically, that stars like this should exist since the 1980s,” Professor Don Kurtz, a co-author of the study from the University of Central Lancashire, said in a press release. “I’ve been looking for a star like this for nearly 40 years, and now we have finally found one.”

What’s next? The team figures that it’s only a matter of time before TESS finds more of these stars.

“Beyond its pulsations, there doesn’t seem to be anything special about this system, so we expect to find many more hidden in the TESS data!” Saul Rappaport, a co-author and professor emeritus of physics at the Massachusetts Institute of Technology, said in a statement.

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ISS is viewable in the Toronto night sky this week – The Loop

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For those in the Greater Toronto Area desperate for something to do this week, it might be time to dust off the telescope.

According to NASA’s SkyWatch website, the International Space Station will be viewable in the night sky this week as it flies between the area and the moon.

NASA’s data shows the ISS is scheduled to fly directly over downtown Toronto every night this week, with two passes on Thursday and Saturday. The space station will also be viewable in Toronto on Monday and Wednesday next week.

The areas surrounding Toronto, such as Pickering, Brampton and Burlington will also be able to view the station, although not as frequently and at slightly different times of night.  

NASA said the station will look like an airplane moving across the sky, except it doesn’t have flashing lights and will be moving considerably faster than an aircraft.

Stargazers will have to be ready, however, as the space station is only expected to be viewable for a couple of minutes each night.

For a list of exactly when the ISS will be visible, click here.

More on this story from CTVNews.ca

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Watch NASA's James Webb Space Telescope unfold its golden mirror for the 1st time (video) – Space.com

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NASA’s next great observatory, the James Webb Space Telescope, has fully deployed its primary mirror for the first time, marking another milestone on its journey to space.

Before all work on the next-generation instrument, which is scheduled to launch in 2021, was paused due to the COVID-19 pandemic, technicians and engineers at the agency were going through a series of tests with the telescope before it’s sent to French Guiana for liftoff aboard an Ariane 5 rocket

Recently, in one of these tests, the space telescope successfully extended and unfolded its entire 21 foot 4-inch (6.5 meters) primary mirror (the largest mirror of its kind that NASA has ever built). The mirror opened up into the same configuration that it will once the telescope is in space.

Related: Building the James Webb Space Telescope (gallery)

NASA’s James Webb Space Telescope has successfully deployed its giant primary mirror for the first time. It will launch in 2021.  (Image credit: Chris Gunn/NASA)

During the test, Webb’s mirror was hooked up to specialized gravity-offsetting equipment that simulated the zero-gravity environment in space. So, not only did the mirror deploy as designed, it did so in a space-like environment, demonstrating its readiness. Engineers and technicians will deploy Webb’s primary mirror only one more time before it’s shipped off to its launch site. 

Passing this test “is another significant milestone showing Webb will deploy properly in space. This is a great achievement and an inspiring image for the entire team,” Lee Feinberg, optical telescope element manager for Webb at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said in a statement

Webb’s primary mirror is a critical piece of the instrument. A telescope’s sensitivity is directly related to the size of its mirror, which determines how much light the telescope can collect from the objects it observes. So, Webb’s mirror has to be really big in order for the instrument to be as powerful as possible. Webb’s mirror is so big that it cannot fit inside of a rocket while fully extended, so it needs to fold up in order to be transported to space. So it’s ability to fold up and then unfurl, ready to get to work, is crucial.

With the COVID-19 pandemic still very much underway, the regular workflow at NASA has been interrupted. Recently, NASA administrator Jim Bridenstine announced that all NASA employees who are not considered essential mission personnel would be working remotely for the time being. 

For now, the Webb team from Northrop Grumman is still continuing integration and testing work in California, though they have shifted to reducing the number of people working at a given time, according to the statement. After the deployable tower assembly is set up in April, integration and testing will be fully stopped as a significant amount of NASA personnel are required for those operations. 

Follow Chelsea Gohd on Twitter @chelsea_gohd. Follow us on Twitter @Spacedotcom and on Facebook.

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ISS is viewable in the Toronto night sky this week – CTV News

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TORONTO —
For those in the Greater Toronto Area desperate for something to do this week, it might be time to dust off the telescope.

According to NASA’s SkyWatch website, the International Space Station will be viewable in the night sky this week as it flies between the area and the moon.

NASA’s data shows the ISS is scheduled to fly directly over downtown Toronto every night this week, with two passes on Thursday and Saturday. The space station will also be viewable in Toronto on Monday and Wednesday next week.

The areas surrounding Toronto, such as Pickering, Brampton and Burlington will also be able to view the station, although not as frequently and at slightly different times of night.  

Stargazers will have to be ready, however, as the space station is only expected to be viewable for a couple of minutes each night.

For a list of exactly when the ISS will be visible, click here.

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